The sides of ∆abc are 30 units, 40 units, and 60 units long. the corresponding sides of ∆xyz are r times as long as the sides of ∆abc. the expression that gives the perimeter of ∆xyz is . if the area of ∆abc is n square units, the area of ∆xyz is square units. nextreset

The perimeter of ABC = a + b + c, where a, b, c are the sides of the triangle. 
The perimeter is 30 + 40 + 60 = 130

The perimeter of XYZ is r*a + r*b + r*c,
Factoring: r (a + b + c) 
We know that a + b + c = 130, so...
Perimeter XYZ = 130r

Area:
The scale factor of the triangles is r
If two similar triangles have a scale factor of r, the ratio of their scale factors is 1:r²
The area of triangle ABC is n²
The area of triangle XYZ is, therefore, r²*n² units
Answer is (r²)(n²) units

The answer would be d i think but i’m for sure it is not a and c

In all honesty, there really is no “work” per say to show. mainly it’s just using the process of elimination. the question is asking which domain(s) would be the most appropriate for the function c(n). n is the number of observed vehicles so right away, 1, 2, and 3 can be eliminated.why? 1, 2 start in the negatives and therefore it is impossible to observe negative cars. so, #4 would be the best answer to the given problem.